What is the least common multiple of 40 and 20? Another way to say this is: $\lcm(40, 20) = {?}$
The least common multiple is the smallest number that is a multiple of 40 and 20. We know that 40 x 20 (or 800) is a common multiple, but is it the least common multiple? Write out the multiples of 40 until we find a number divisible by 20. 40, So, 40 is the least common multiple of 40 and 20.